1. Field of the Invention
The present invention relates to a method for detecting nucleic acid hybridization, in which electrochemiluminescence is promoted by using intercalator which is peculiarly binding only to double-stranded nucleic acid.
2. Description of the Background Art
Methods for detecting a result of nucleic acid hybridization generally include nucleic acid hybridization detection methods by a radioautography, a laser-induced fluorescence (LIF) and an electrochemical method.
The radioautography method which detects nucleic acid hybridization by labeling target nucleic acid as radioactive isotope is the most widely used in molecular biology. 32P is used as the radioactive isotope, and photographic films are used to detect a binding state of target oligonucleotide and probe oligonucleotide which are labeled. The radioautography method does not require much basic knowledge, thereby easily being applied. However, the radioautography method has several disadvantages that long analysis time such as several hours and a day makes it impossible to know a result fast, a resolution ability is low with orders of 0.1˜10 μm, and radioactive isotope used in excitation is not stable.
Recently, a laser-induced fluorescence (LIF) method is much used in DNA hybridization detection because several kinds of fluorescence material is used, a resolution ability is excellent, and a result is immediately known. Nowadays, if a charge coupled device (CCD) camera to which fluorescence analysis and image technique are combined is introduced, molecules labeled as fluorescence materials can be imaged real time. However, said method also has several disadvantages that DNA of a sample has to be labeled as fluorescence material before measuring the DNA of a sample, a process to separate and refine the DNA is complicated, a stability for experiments is required, and expensive equipments such as a laser and an attached device for optical detection and an expensive image scanner for scanning a two-dimensional substrate are required.
The method for detecting DNA hybridization by an electrochemical method is one to detect DNA hybridization by using a binding of metallic complex having activity electrochemically and double-stranded DNA. Even if the method is enough simple to provide a cheap detection apparatus, sensitivity is not good.
Since the aforementioned conventional methods for detecting nucleic acid hybridization have several disadvantages, a new detecting method having a high sensitivity is necessary. Especially, a development of a small and cheap system for detecting nucleic acid fast without a process that a sample is bound to label material is required as a portable diagnosis device.